1. Field of the Invention
The present invention relates to a pedestrian protecting device for a vehicle, which is provided with an airbag folded and housed on the lower side of the hood panel near the rear edge so that it can be expanded and inflated to protrude upward by admitting an inflating gas discharged from an inflator, thereby to protect a pedestrian.
2. Description of the Related Art
Pedestrian protecting devices of the aforementioned construction found in prior arts include an airbag device having the construction disclosed in Unexamined Published Japanese Patent Application No. 7-108903. The airbag device described in FIGS. 7 and 8 of that Application is provided with an airbag to be folded and housed, and a door portion for covering the upper side of the airbag. This airbag is folded and housed into an elongated shape below and along the lower edge of the hood panel. The door portion can be opened toward the vehicular rear when the airbag is expanded and inflated. In the vehicle having this airbag device arranged, the hood panel is so curved on its rear edge side that its transverse center may protrude to the front along with the curved shape of the lower edge of the front windshield. In this airbag device, therefore, the door portion covering the upper side of the folded airbag is also formed in a curved elongated shape along the rear edge of the hood panel.
Specifically in the airbag device of the aforementioned construction, the hinge portion on the door portion near the rear edge for providing the center of rotation when the door portion is opened is arranged with a curvature following the curved shape of the door portion. This is because the door portion is curved and elongated. At the expansion time of the airbag, therefore, the door portion may be hard to smoothly open, making prompt expansion of the airbag difficult.
In the aforementioned construction, moreover, the airbag device has to be assembled considering the interference of the hood panel with the door portion when the hood panel is opened/closed. This is because the door portion is arranged on the rear edge side of the hood panel itself. Therefore, it is troublesome to assemble the airbag device into the vehicle.
Another pedestrian protecting airbag device has the construction disclosed in Unexamined Published Japanese Patent Application No. 2000-264146.
This airbag device is housed in the recess which is formed by a cowl panel positioned between the hood panel and the front windshield of the vehicle. The airbag is expanded and inflated to cover the front sides of the front pillars and the wipers by admitting the inflating gas from the inflator.
However, the airbag device of the aforementioned construction is made absolutely separate of integral members of the vehicle. For this airbag device, therefore, a case for housing the airbag and the inflator, a door portion covering the airbag and adapted to be opened when the airbag is to be expanded and inflated, and so on are indispensable. And, the airbag device thus constructed is housed, as one unit comprising the case housing the airbag and the inflator, in the recess formed of the cowl panel. Therefore, the number of parts of the entire vehicle is increased and makes no contribution to the reduction in the number of assembling steps, thus increasing the weight of the vehicle.
In the pedestrian protecting device thus constructed, moreover, the airbag completes its inflation by extending obliquely backward and upward from the lower side of the hood panel. At this time, the airbag pushes up and supports the rear end of the hood panel so as to apply a shock absorbing action to the hood panel, and covers the front faces of the hard front pillars.
In connection with the airbag of the device of the prior art, however, the following problem arises, in case the portion to push up and support the rear end of the hood panel is so modified in construction as to cover the cowl louver between the hood panel and the front windshield of the vehicle widely in the longitudinal direction of the vehicle. Specifically, the portion of the airbag which pushed up and supported the rear end of the hood panel before modification is now formed into a simple cylindrical shape. If the cowl louver is still to be covered widely in the vehicular longitudinal direction by that portion, therefore, the diameter of that cylindrical portion must be enlarged, increasing the volume of the airbag unnecessarily. As a result, the time period from the start to the end of the expansion of the airbag is elongated, and the most preferred inflator for feeding the airbag with the inflating gas needs to be replaced by one of a high output.
In the construction of recent years to improve the design of the vehicle, moreover, the arms of the wipers when not used are housed on the lower side of the hood panel rear edge. In the vehicle having the pedestrian protecting device of that construction mounted thereon, however, the arms of the wipers are arranged between the recess and the front windshield (see FIG. 2 of the aforementioned Application). In other words, the arms of the wipers are exposed even in the unused state to the outside of the vehicle. It is, therefore, difficult to apply the pedestrian protecting device of the prior art to the vehicle of the type using wipers which are provided with the arms to be housed when not used on the lower side of the hood panel. This is because the wipers then make it difficult to retain the smooth expansion of the airbag.